Another consideration being self-employed is losing the 9-5 employer's 401K. Sure there are plans for the self-employed, but many employers offer some kind of matching percentage. I always maxed out my 401K contributions over the years and am glad I did. If you may already have an IRA, you've at least got something to supplement Social Security (assuming it's still viable in 20-30 years.)
Retirement looks a long way off at 41, but it sneaks up on you...
Rusty